from django.contrib.postgres.search import SearchVector
from django.core.paginator import Paginator,EmptyPage,PageNotAnInteger
from django.shortcuts import render , get_object_or_404
from django.core.mail import send_mail
from  .models import Post 
from .forms import EmailPostForm,CommentForm, SearchForm
from taggit.models import Tag
from django.db.models import Count

def post_list(request,tag_slug=None): 
      posts = Post.published.all()
      tag = None
      if tag_slug:
       tag = get_object_or_404(Tag, slug=tag_slug)
       posts = posts.filter(tags=tag)
      paginator = Paginator(posts,3)
      page = request.GET.get('page')
      try:
            posts = paginator.page(page)
      except PageNotAnInteger:
            posts = paginator.page(1)
      except EmptyPage:
            posts = paginator.page(paginator.num_pages)
      return render(request,'blog/post/list.html',{'posts':posts,'page':page,'tag': tag})
def post_detail(request, year, month, day, post):
 post = get_object_or_404(Post, slug=post, status='published',
 publish__year=year,
 publish__month=month,
 publish__day=day)
 comments = post.comments.filter(active=True)
 new_comment = None
 if request.method == 'POST':
      comment_form = CommentForm(data=request.POST)
      if comment_form.is_valid():
            new_comment = comment_form.save(commit=False)
            new_comment.post = post
            new_comment.save()
 else:
      comment_form = CommentForm()
 post_tags_ids = post.tags.values_list('id', flat=True)
 similar_posts = Post.published.filter(tags__in=post_tags_ids)\
  .exclude(id=post.id)
 similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
  .order_by('-same_tags','-publish')[:4]
 return render(request, 'blog/post/detail.html', {'post': post,'comments': comments,'new_comment': new_comment,'comment_form': comment_form,'similar_posts': similar_posts})
def post_share(request, post_id):
 post = get_object_or_404(Post, id=post_id, status='published')
 sent = False
 if request.method == 'POST':
     form = EmailPostForm(request.POST)
     if form.is_valid():
         cd = form.cleaned_data
         post_url = request.build_absolute_uri(post.get_absolute_url())
         subject = f"{cd['name']} recommends you read " \
                    f"{post.title}"
         message = f"Read {post.title} at {post_url}\n\n" \
                    f"{cd['name']}\'s comments: {cd['comments']}"
         send_mail(subject, message, '1516601492@qq.com',[cd['to']])
         sent = True
 else:
     form = EmailPostForm()
 return render(request, 'blog/post/share.html',{'post': post,'form': form,'sent': sent})
def post_search(request):
 form = SearchForm()
 query = None
 results = []
 if 'query' in request.GET:
   form = SearchForm(request.GET)
   if form.is_valid():
      query = form.cleaned_data['query']
      results = Post.published.annotate(search=SearchVector('title', 'body')).filter(search=query)
 return render(request, 'blog/post/search.html', {'form': form,'query': query,'results': results})